Relay system for controlling interpole excitation of rotary converters



June 1 1926. r 1,536,711

' E. B. SHAND RELAY SYSTEM FOR CONTROLLING INTERPOLE EXCITATION OE ROTARY CONVERTERS .Filed Oct. 16. 1922 WITNESSES: INVENTOR Err B. SI and. B

Patented June 1, 1926.

UNITED stares PATENT OFFICE.

ERROL B. SHAND, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR'TO WESTINGHOUSE ELECTRIC 8n MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

RELAY SYSTEM FOR CONTROLLING INTERPOLE EXCITATION 0F ROTARY CONVERTERS.

Application fi1cd 0ct0ber 16, 1922. Serial No. 594,735.

force being derived, according to my inven tion, by means of a spring carried by a movable support which is adjusted in position in accordance with the adjustment of the controlled apparatus. v

A further ob 'ect of my invention is to provide a system for controlling the excitation of an auxiliary commutating winding on a rotary converter utilizing a relay of the type just described.

lVith these and other objects in view, my invention consists in the methods and apparatus hereinafterv disclosed and specifically recited in the appended claims.

The single figure of the accompanying drawing is a diagrammatic viewof circuits and apparatus embodyingmy invention in what is believed to be a preferred form.

The present invention is an improvement upon that covered by my application, Serial No. 551,538, filed April 11, 1922, wherein is described a method of and means for adding a component of interpolar excitation to a rotary converter in accordance with the direction and the magnitude of the wattless current components drawn by the converter, the ratio of the added interpolar excitation to the wattless-current components being varied in accordance with the energy component of the load, in order to compensate for variations in the armature reaction resulting from changes in the angular position of the rotor. under, difiere nt load conditions. 7

In the drawing is shown a rotary converter 4, having an armature 5, which is connected. to an alternating .jcurrent line. 6

and to a direct currentline 7. The converter is also provided with three field windings, to-wit i an exciting winding8 which is con nected acr'oss the direct-currentline through a rheostat a series'commntating field wind/'- .conductors of the direct-current line 7.

ing 10 and an auxiliary commutating field I winding 11.

The auxiliary winding 11 is excited from double-dialrheostat 12 having its terminals connected across the direct-current line 7 and having movablearms 18 and 14-.connected to the respective terminals'of said winding 11. The position of the movable arms 13 and 1 1 is controlled by means of a direct-current motor 15 having one brush terminal connected to the mid-point 16 of the rheostat 12 and having the other brush terminal connected to a switch arm 17 ofa controlling element 18, said switch arm 17 being adapted to engage either the one or the other of two stationary contact members 19 and 2( which are connected, respectively, to the two. The motor 15 has a field winding 21 shown as being permanently connected across the direct-current main 7.

The switching device 18 may be a Siemensdynamometer or a. Kelvin-balance device, shown'as comprising a movable coil 22 carried by the switcharm 17 and a pair of stationary coils 23. disposed on opposite sides thereof. The movable coil 22 is energized across two of the conductors of the alternating-current line 6 and it cooperates with the stationary coils 23 which are energized from a currenttransformer 24c in another of the conductors of the, alternating-current line (3 in such manner that the coils 22 and 23 de velop a torque proportional to the wattless componentof the alternating current.

A variable resistor 25 is connected in se ries'with the coil 22, or with the coils 23, and it is automatically controlled by means of any suitable current-responsive device, such as a so-called torque motor 26, which is a direct-current motor having an armature winding 27 energizediacross the direct-current line 6 and having a field winding 28 energized in any mannerin accordance with the direct-current load. The field winding 28 is shown connected in shunt with 1 the is thus a function of the product of the reactance" component of alternating currentand the direct-current output, the torque bein g increased as the load is increased.

ll hen the relay device 18 is moved out of its neutral or zero position, the movable switch arm 17 is brought into contact with the one or the other of the stationary contact members 19 and 20, thereby energizing the motor 15 in the proper direction to make a compensating adjustment of the double-dial rheostat 12. As the movable arms 13 and 14; of the r-heostat- 12 are adjusted, in order to vary the current in the auxiliary commutat-ing coil 11, a lever arm 29, extending from the movable arm 13, operates sliding sup.- porting member 30, which moves in a guideway 31 and supports a coil spring 32 or other resilient biasing device.

The center of the spring 32. is connected to the movable switch, arm 17. of the controlling element 18, and thus the biasing torque, tending to returnfthe switch. arm. to zero or neutral position, is. increased in accordance with the adjustment of the double-dial rheostat 12. he values of. the resistances between the successive segments of the double-dial rheostat are so chosen with respect to thespring that the movable arm 17 is always brought back to zero position at the instant that the current in the coil 11 reaches. the proper value covrespending! to the. adjusting torque dev loped lictweenthe coils. 91 and 2..

Whilcl have docribed a specific term 0 F1 embodiment oi my invention. it will be obvious that many changes and substitu'ions oi" equivalents may be made by those in the art without departing from the essential features of my invention. I donot desire, thcretord to be limited to the spe cific construct-ions. shown. except in. so tar; as may be required by the language ot the. appended claims when readin the light. of: the prior art.

I claim as my invention:

1. In combination with a wntrolling app:- ratus andl a controlled. circuit an electric balance device comprising a movable contact arm and elcctro-dynainic mcanstor producing a force, tending to more. said contact arm in either direction, in rcsnonse to the condition of said controlling apparatus, a

pair of contact-malring. elements on opposite.

sidcs u said contact: arm, separate power means controlled by. said contact-nialnng elements for maltag, a desired.ad ustm ntin the conditions btaining inv the controlled ci rcui t, spring in eansh aving. itsc ntral point connectedv to said. movable contact arm for bringing. back said contact arm to. normal neutral position... relative to said contactmakin elements, and a, mechanical connection driven by said, separate; power means for changing the relative positions of the central point. of, the sprin means;

peutral ai isw bet-esteem co elements, whereby said contact-arn'i is brought to neutral out-ot-contact position whenever the movement of said separate power means has adjusted said controlled circuit an amount corresponding to the force produced. by the clectrodynamic means at any instant.

2. The combination with a rotary converter having a commutating field winding, of means for varying the field produced by said commutating field winding, and means for controlling said last-mentioned means comprising an element having coils cnergizcd by the altcrmiting voltage and alternating current of said converter so as to be responsive to the wattless component of the alternating current, and an. adjustable spring, means mechanically connected: to said ficld-varying means and to said" controlling means.

3. The combination with a rotary, converter. having a. commutating field winding, ofmeans for varying the; field produced by said commntating Iield winding, and means for controlling. said last-mentioned means com prising ani element having coils energized: by the alternating voltage and alternating current of said converter so. as to be responsive to the wattless con'iponcnt of the alternating current; means for, in ctlect, varying the lIUIJQClZLIICQ ot the. circuit of one of said coils, and an adjustable springnieans mechanically connected to said fieldsvarying means and to said controlling means.

41- Tu C(Jll'llilllitll011,- alternating.-current mains, direct-cnrrent mains, a rotary convcrtcr connected thereto and having av commntating field winding. a double-dial rheosait having arms and being connected across said direc :urrent mains, said commutating field. winding being connected to said arms of said rheostat. regulating means for controlling said double-dialrheostati a contact-makingdevice for controlling. said'regulating, means and having an elen'ient res-ponsive to. the, wattless'component of the alterating current taken by saidv rotary converter, and an. adjustable spring means-operating.upon-said contact making device and iiieriianically connected to said regulating means.

In combinatiom alternatingcur-rentma direct-current mains. a rotary conelement in accordance With the energy load current, and an adjustable spring means operating upon said contact-making device and mechanically connected to said regulating means.

6. A Siemens dynamometer, contacts thereon for controlling a motor upon departure in either direction from zero reading and spring means operated by the movement of said motor for restoring the dyna- 10 mometer to zero reading.

In testimony whereof I have hereunto subscribed my name this 7th day of October, 1922.

ERROL B. SHAND. 

